A NOTAM is warning operators of “all aircraft relying on GPS” of widespread GPS outages starting Tuesday throughout the Southwest and especially southern California. The tests will potentially knock out all GPS-reliant services including WAAS, GBAS and, ADS-B. Specifically called out is potential impact to EMBRAER PHENOM 300 a/c. (www.avweb.com) 更多...

It is unfortunate that FA lack a sarcasm font. Ignore the man behind the curtain is from the scene in Wizard of Oz where Toto pulls the curtain to reveal the wizard at the controls.As for "Nothing to be seen here..." see:http://tvtropes.org/pmwiki/pmwiki.php/Main/MoveAlongNothingToSeeHere

These are common cultural concepts with which I would expect you to be familiar.

I have a friend, a mathematician and fellow ham, specializing in mapping and GPS systems, who works for DoD and who has been doing work "out west" for the past couple of years that he won't discuss at all. Looks like his stuff has gotten to the testing stage.

I am not clear what your connection to GPS is. You think we in aviation are "paranoid" for our dislike of having our expensive on-board nav. systems rendered useless for such an extended period of time ?

May I inquire ? How do YOU use GPS? In my own case, I recently had my entire panel revised..I still have two VORS, so I am still able to navigate. But my ADF receiver, my LORAN, all gone. Can you tell us more about YOUR aircraft's nav. systems and how YOU plan to get by during this very upsetting outage ?

Hi Mr. Wiley:I presume you are a "flyer" (meaning someone who rides in BACK of a "Part 121" provider), and thus, for lack of understanding about what we do in aviation, are frightened at the possibilities you raise.

Let me assure you that you "flyers" are perfectly safe. We who drive airplanes around have any number of ways to avoid the kind of danger you propose.

I am not entirely sure I understand what you mean by "FL120". Are you concerned about people driving airplanes around at something called Flight Level Twelve Thousand Feet" around the SIerra Nevada? Or did you mean "Flight Level One Hundred Twenty Thousand Feet...?

If you meant 120,000 ft., don't worry....the highest peak out here in the south-west is Mt. Whitney...around 14,000 ft. So in that case, you are perfectly safe.

If you meant twelve thousand feet...again..don't worry...we in the aviation community have all manner of rules, regulations, and proceedures for "IFR" ( presumably you meant INSTRUMENT FLIGHT RULES ?) We have things called "charts" - these can either be paper or electronic that are independent of the GPS system. They tell us what "MINIMUM OBSTRUTION CLEARANCE" altitudes are in any given sector. Over the Sierra Nevada, for example, those MOS's are high enough over the highest peaks to keep you perfectly safe!

So - absent the VERY statistically rare case ( dosnt seem to happen any more what with more people flying IFR and knowing what they are doing)...you are perfectly safe.

As far as a shut-down of the entire GPS system in any given sector...- yes...that will happen later this month for a short time for a test of GPS security... - but it dosnt happen without weeks of prior warning. We have what we call "NOTICES TO AIRMEN" which we are required by law to check.

Of course there is the remote possibility of a electrical failure on board an aircraft, disabling the GPS receivers in that aircraft.

Everyone I know carries a "hand-held back-up" I carry a hand-held Garmin 500 (look that up on Garmin's "site".....may put your mind to ease about how things work in aviation ) AND I carry an I Pad. Which gives me all manner of information independent of the GPS (although obviously the info. is more complete when it is receiving GPS).

So again...not to worry...we have totally independent systems NOT dependent on an aircraft's electrical system and/or GPS.

I am confused at what you are getting at, and who you are using an example in your too-brief post " DEPENS ON HOW MUCH HE LIKES PAIN". I hope you were not attacking fellow "flyer" Joel Wiley. I don't think he meant to be hostile in his questions about GPS and his comments.

He explained he lost friends in a major airline accident. I hope you are not making fun of him because he confused the Teneriffe accident with our GPS discussion.

It is normal, natural, and quite human for the "flyers" to have a deem emotional concern about aviation. Why shouldn't people who, when "surfing the internet", think a site entitled FLIGHT AWARE is a place where they can ask questions about aviation.

True, we have to expect some silliness from folks - hopefully, they are adult enough to recognize that if they make a silly post in a technical site, they could get chastised.

Again, best thing to avoid ridicule ( I presume that is the kind of "pain" you are referring to, is ask QUESTIONS about aviation - unless you are qualified to give your OPINION on some technical matter, leave that to those of us who DO have a legit connection to aviation.

You also are confused about my Tenerife comment which was not about GPS but in response to your assertion and assurance that 'flyers' are pefectly safe.BTW, what is your opinion on what constitutes "a legit connection to aviation"?

You asked a question about aviation and GPS. You are entitled to an explanation. Apparently, you weren't sincerely nor seriously interested in the technicalities of aviation ; just wanted to be "part of a group of flyers"...I understand that.

However, others who may like to come in here, but are too shy to ask questions, also have a right to be concerned about what we do in aviation.

So, each time you make a post that might seem reasonable to the uninformed, but also absurd and even childish, I will certainly try and explain whatever aspect of real aviation you bring up, in the hopes of reducing anxiety for the "fliers" in here.

I mistyped the flight level, the main issues with FL120 being pressure and a bit of occasional space debris.

That 'flyers' are 'perfectly safe': I must take that assertion with a grain of salt, with the loss of a casual acquaintance in the Tenerife incident. 583 'flyers' were not 'perfectly safe'. I was responding to your assertion of 'paranoia'. You mention that you carry a Garmin 500, and an Ipad. I would include those in the 'prudent' category.

Thank you for your brief overview tutorial on aeronautical charts. The area covered by the area I mentioned is the San Francisco chart. I am sure it will be of benefit to at least three 'flyers'.

SILLY ? I disagree. As more and more of us actually involved in aviation depend on GPS, its reliability becomes more critical. Not to even mention how many ground-based users there are for so many legit. purposes.

I certainly understand why our government needs to know about how GPS can be degraded, and how the "degraders" can be dealt with.

I am more than a little bit puzzled at how extensive both in time and distance this disruption will be. With my admittedly limited knowledge of sophisticated electronics, I find it difficult to understand why it would take more than a one-day session to experiment both with various interference / "spoofing" aspects. and counter-measures, PROVIDED THE GOVT. KNEW WHAT IT WAS DOING, AND PLANNED EFFICIENTLY.

Interesting side-note - by law once we are equipped with ADS-B, we are NOT ALLOWED to turn the thing off - we MUST have our system report who and what we are.

So the government is going to disable the system that gives it all that knowledge about who is operating their aircraft where....?

Guess you are not aware that lots of airplanes of all shapes and sizes now use GPS for navigation. While it is not the only form of electronic navigation, it is clearly the most accurate and thus safest. True, in order to be a pilot you have to study and pass a test showing you can navigate by other means, but the fact is this is going to be a inconvenience for a lot of people..